The field of the invention is tools with the preferred embodiments being particularly adapted for use in the field of orthodontic bracket placement, positioning, and alignment tools.
Dentists, orthodontists in particular, often use orthodontic hardware such as brackets and archwires in the prevention or correction of irregularities of the teeth. An orthodontic bracket is generally a metal or ceramic part fastened to a tooth to serve as a means for fastening an archwire. An archwire is a metal wire that is attached to the brackets to move the teeth of a patient in a manner desired by the patient""s dentist. An example of a bracket and archwire assembly is shown in FIG. 1 with bracket 10 being bonded to tooth 40, and archwire 20 being coupled to bracket 10 by ligature wire 30. Bracket 10 comprises base 11, and stems 12 and 13. Stems 12 and 13 each comprise two tie wings (12A, 12B, 13A, and 13B) and an archwire receiving slot (12C and 13C). In FIG. 1, bracket 10 can be characterized as having perpendicular axis A1 and A2, and tooth 40 can be characterized as having a central axis A3, and an occlusal plane P1 as shown.
Due to the small size of the brackets, it is generally desirable to use a holder such as a tweezers or pliers to pick up position bracket 10 on a tooth 40. The positioning and alignment of bracket 10 relative to tooth 40 is particularly important to a dentist, as it tends to strongly impact the movement of tooth 40 during treatment. As such, it is generally desirable to position bracket 10 at a particular height relative to the top/occlusal surface of the tooth. Referring to FIGS. 2A-2C, the position of bracket 10 may be adjusted such that: (a) the vertical distance D1, the distance between the occlusal plane P1 or occlusal surface of tooth 40 and horizontal axis A2, is a desired value; (b) the horizontal distance D2, the horizontal component of the distance between axis A1 of bracket 10 and axis A3 of tooth 40, is a desired value (possibly zero); and the angle E1 between axis A1 and axis A3 is a desired value (also possibly zero). Unfortunately, properly positioning and aligning bracket 10 is not always easy to accomplish. Because of this, tools for aiding in the holding, positioning, and aligning of brackets have been developed. Examples of such tools can be found at least in U.S. Pat. Nos. 5,868,787 and 4,850,864, in U.S. Pat. No. 5,810,582 and in U.S. Pat. Nos. 6,296,482, 5,312,248, and 5,304,061. However, this list is not exhaustive as other types of holders, gauges, and other tools are also known.
One type of holder that is particularly suitable for comparison purposes is the bracket holding tweezer of FIG. 3. In FIG. 3, tweezer 50 comprises a pair of elongated members 51 and 51xe2x80x2 placed in an adjacent lengthwise relationship with one another, each member having a first end part 52 and 52xe2x80x2 and a second end part 53 and 53xe2x80x2, the first end part forming a gripping mechanism 54, and the second end parts coupled together to form a handle 55. The tweezers of FIG. 3 is a pre-tensioned or cross-over type having a gripping mechanism 54 comprising a jaw which is held in the closed position by tension formed by the shape of the tweezers, in particular by the cross-over portion 56 and the coupling together of ends 53 and 53xe2x80x2. The user must apply pressure to the members 51 and 51xe2x80x2 to open the jaw, align the object upon which the tweezers are to be used with, and then reduce the pressure on the members so that the object is held by the gripping area. In many instances, cross-over type holders are preferred in the placement of brackets on teeth.
The gripping jaw 54 that includes the first end parts 52 and 52xe2x80x2 of the members 51 and 51xe2x80x2, includes gripping surfaces 57 and 57xe2x80x2 having front edges 58 and 58xe2x80x2 that are typically used to grip the tie wings of an orthodontic bracket. The front edges 58 and 58xe2x80x2 of the gripping jaws are typically inclined relative to a vertical axis to allow the holder to be angled away from the surface of a tooth during placement of a bracket. In some instances their front edges are cutting surfaces.
The present invention is directed to apparatus for holding, positioning, and aligning other apparatus such as orthodontic brackets. Preferred embodiments of such apparatus include one or more of the following: (a) a bracket gripping mechanism; (b) a horizontal position indicator; (c) a vertical position indicator; and (d) an orientation indicator. In preferred embodiments, various portions of the apparatus serve multiple purposes, and interact with other portions to facilitate use of the apparatus. A most preferred apparatus comprises a handle, a bracket gripping mechanism, a combined orientation and horizontal position indicator, and a height gauge (vertical position indicator) that can also cooperate with the handle as an orientation indicator.
It is advantageous for a given apparatus to comprise an indicator that extends vertically upward and/or downward from the apparatus with the indicator providing a visual representation of the location of a centerline of a bracket or other apparatus being positioned. It is also advantageous to have such an indicator be non-perpendicular to a handle portion of the apparatus. If an apparatus comprises jaws, it is advantageous to position a vertically extending indicator between the jaws such that the indicator is positioned at or near the center of the gap between the jaws when the jaws are being used to hold a bracket or other apparatus. If an apparatus comprises a holder having angled jaws, it is advantageous to have such a vertically extending indicator be parallel to the jaws so as to provide a visual indication of the orientation of the jaws. Any vertically extending indicator is preferred to be near an end of a given apparatus to allow it to be close to a bracket or other apparatus being positioned and orientated. However, in the case of an orthodontic bracket holder, it is preferred that such vertically extending indicator be set at least slightly back from an end of the holder so as to avoid contact with the teeth and gums of a patient during use.
It is advantageous to be able to use most of the length of an elongated apparatus to provide a visual indication of the orientation of a bracket or other apparatus being positioned as the longer the indicator means is, the easier it is to determine improper orientation of the apparatus being positioned.
It is advantageous to include both position and orientation indicators on a holder apparatus so as to allow a bracket or other apparatus to be positioned and aligned without having to utilize a separate tool. It is contemplated that one advantage of using such an apparatus is that, particularly when dealing with using a fast setting bonding material to bond a bracket to a tooth, proper position and orientation can be obtained earlier during the setting process with a resultant reduction in risk of damage to the bond that that can be caused by movement during later stages of the setting process.
A desirable apparatus can be obtained by modifying an existing bracket holder by adding a height gauge to the handle of a standard bracket holder, and mounting a vertical bar near the jaws of the holder. In such a configuration, the vertical bar can be used simultaneously as both a position and orientation indicator. The height gauge can be used first as a height gauge, and subsequently as an orientation indicator in cooperation with a handle of the holder.
It is preferred that an included height gauge have a bracket contact portion set at a fixed distance from a tooth contacting portion will be advantageous. It is also preferred that the bracket contact portion be adapted to fit within the archwire receiving slots of the stems of a bracket, and, preferably, to comprise a wire loop or other mechanism that permits the bracket holder to be positioned horizontally while being received by the archwire receiving slots even if such slots are tilted upward or downward.
When a height gauge is part of a bracket holder, rotating the height gauge ninety degrees relative to the jaws of the holder will, in many instances, position the holder relative to the gauge so as to best cooperate with the gauge to act as an orientation indicator.
If a bracket holder apparatus comprises multiple planar members adapted to be partially inserted into a bracket or other apparatus, it is preferred that the members be co-planar and positioned relative to the remainder of the apparatus so as to best use the remainder of the apparatus of the orientation of the planar members.
It is contemplated that it is advantageous to provide orthodontic bracket holders in sets with each holder in the set being dedicated to positioning a bracket on a particular tooth, and each holder having a height gauge set to a fixed height that corresponds to the height at which a bracket is to be positioned on the tooth corresponding to the holder.
Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.